JPS6348545B2 - - Google Patents

Description

Claim 1: An absorbent material comprising a water-insoluble hydrocolloidal polyelectrolyte and absorbing an aqueous liquid several times its weight, with the general formula: (In the above formula, Y is a hydrogen atom, linear or branched C ₁ - _{C 8}
an alkyl group or a _C3 - _C6 -cycloalkyl group, R is a hydrogen atom, a C1- _C4 -alkyl group or a halogen, and R' is a hydrogen atom, _{a C1} - _C4 -alkyl group or a halogen ) at least one isothiazoline-3 represented by
- The above absorbent material containing an on derivative. 2 Y is a hydrogen atom or a _C1 - _C4 -alkyl group, R is a hydrogen atom or a _C1 - _C4 alkyl group, and R' is a hydrogen atom, a _C1 - _C4 -alkyl group or a halogen; Absorbent material according to certain claim 1. 3. Absorbent material according to claim 2, wherein Y is a methyl group, R is a hydrogen atom and R' is a hydrogen atom or a methyl group or a halogen. 4 At least two of the following isothiazolines -
3-one derivatives: A - at least one of which corresponds to the formula in which R' is a halogen, and B - at least one of which corresponds to the formula in which R' is a hydrogen atom or
Absorbent material according to one of the preceding claims 1 to 3, corresponding to the formula which is a _C1 - _C4 -alkyl group. 5 The following two types of isothiazolin-3-one derivatives: An absorbent material according to claim 4 containing. 6. Absorbent material according to claim 4 or 5, wherein the A/B molar ratio is from 0.5:1 to 8:1. 7 1.5 to 750ppm based on polymer electrolyte
7. An absorbent material according to any of the preceding claims, containing a weight of isothiazolin-3-one derivative. 8 7.5 to 450ppm based on polymer electrolyte
8. An absorbent material according to claim 7 containing an amount of isothiazolin-3-one derivative by weight of . 9. Absorbent material according to any of the preceding claims 1 to 8, in which an isothiazolin-3-one derivative is combined with a salt of a transition metal. 10. Absorbent material according to claim 9, wherein the transition metal is selected from copper and zinc. 11. Absorbent material according to claim 9 or 10, wherein the weight ratio of isothiazolin-3-one/transition metal salt is from 0.012:1 to 0.018:1. 12 An absorbent substance consisting of a water-insoluble hydrocolloidal polyelectrolyte and capable of absorbing an aqueous liquid several times its weight, having the general formula: (In the above formula, Y is a hydrogen atom, linear or branched C ₁ - _{C 8}
-alkyl group or _C3 - _C6 -cycloalkyl group, R is a hydrogen atom, _C1 - _C4 -alkyl group or halogen, and R' is a hydrogen atom, _C1 - _C4 -alkyl group or At least one isothiazoline-3 represented by
In the method for producing the above absorbent material containing -one derivatives, at least one isothiazolin-3-one derivative is first mixed in 80/2 water/alcohol.
A process for producing an absorbent material as described above, characterized in that a hydrocolloidal polyelectrolyte is added to the mixture in an amount of 0 to 90/10, and then the mixture is filtered. 13. The method for producing an absorbent material according to claim 12, wherein the transition metal salt is added before the hydrocolloidal polymer electrolyte. 14 An absorbent substance consisting of a water-insoluble hydrocolloidal polyelectrolyte and capable of absorbing an aqueous liquid several times its weight, having the general formula: (In the above formula, Y is a hydrogen atom, linear or branched C ₁ - _{C 8}
-alkyl group or _C3 - _C6 -cycloalkyl group, R is a hydrogen atom, _C1 - _C4 -alkyl group or halogen, and R' is a hydrogen atom, _C1 - _C4 -alkyl group or At least one isothiazoline-3 represented by
Absorbent pad for personal hygiene, in particular for diapers or sanitary napkins for infants or incontinent adults, characterized in that it contains the above-mentioned absorbent material containing -one derivatives as superabsorbent. Description The present invention relates primarily to the field of personal hygiene. It is aimed at absorbent substances that consist of hydrocolloidal polyelectrolytes that are insoluble in water and absorb several times their own weight in aqueous liquids. It is also aimed at the uses of this substance and the method for its production. State of the Art Urine, which is initially sterile (unless infected with a urinary tract disease), becomes contaminated by the perineum after leaving the urethra. It is home to a large number of bacterial species, 80% of which are:
Proteus (50%), Klebsiella, Pseudmonas
and coli. Urine is also an excellent substrate for the growth of these bacteria. Similarly, menstrual blood, which contains proteins, various amines, and lipids, serves as a medium for the above-mentioned bacteria. Thus, urea is converted to ammonia by urease possessed by certain bacteria such as Proteus and Klebsiella according to the following reaction: The amino acids that make up proteins similarly undergo degradation, including the production of ammonia. Other substances such as lipids in the blood are also converted to other breakdown products according to the following formula: The fatty acids produced are inter alia butyric acid, isobutyric acid and isovaleric acid. All these reactions that are the result of bacterial action have a common property that they lead to compounds with a very unpleasant odor. In the case of persons with urinary and/or fecal incontinence and menstruating women, this perineal area is in direct contact with the body fluids absorbed by absorbent tampons and, as a result, bacteria on these fluids. produces an unpleasant odor. It is understandable that this phenomenon, which is somehow tolerated in infants, becomes psychologically difficult to tolerate in adults. To eliminate this disadvantage, it has been proposed to add disinfectants to the absorbent pads of diapers and sanitary napkins. Namely, French Patent No. 2490093 (Patentee: LANDSTINGENS INKOPSCENTRAL
LIC EKONOMISK FORENING) describes the impregnation of absorbent pads made from cellulose fibers with water-soluble copper salts, preferably on the surface. Copper in ionic form is known in fact for its bactericidal and fungicidal properties. However, this technique has certain drawbacks. Disinfectants deposited on the pads may irritate the user's skin, resulting in certain skin disorders and reducing natural protection. Furthermore, the industrial application of the above method poses certain difficulties, since it is necessary to treat the entire surface of the absorbent pad. Furthermore, the deposition methods (spraying and powder deposition) pose considerable risks to the operator. Punishu Patent Application No. 0019371 (Applicant:
UNILEVER) is a substance that allows ions of transition metals (such as copper or zinc) to be mixed into the absorbent pad to improve its absorption capacity, as the name suggests.
It is proposed to mix it into the ARA (abbreviated as ARA). An ionic bond is established between the anionic group (particularly COO) and the transition metal ion. This bond is quite unstable, so transition metal ions
ARA may migrate into tampons and cause large protein aggregations. However, in order to achieve migration of these ions to the outside of the ARA, relatively large amounts of incorporation are required. This is because about 80% of the COOH groups are neutralized. This has the disadvantage of controlling the rate of gelation of ARA and reducing its absorption capacity. Furthermore, transition metals such as copper or zinc are known to be bacteriological agents and therefore toxic, and from a toxicological point of view it is preferred that these be present in very low amounts. The object of the present invention is to provide a superabsorbent having a bactericidal action that can be applied to its surroundings consisting of an absorbent pad. This has the advantage of eliminating the risk of irritating the skin before the nutrient solution reaches it. Generally referred to as a “superabsorbant”
The term is a synonym for an additive with improved retention (ARA) or substance that can absorb several times its weight in liquid. General description of the invention The invention is characterized in that the absorbent material contains at least one isothiazolin-3-one derivative of the following general formula: (In the above formula, Y is a hydrogen atom, linear or branched C ₁ - _{C 8}
-alkyl group or _C3 - _C6 -cycloalkyl group, R is a hydrogen atom, C1- _C4 -alkyl group or halogen, R' is a hydrogen atom, _{C1 -C4 -} alkyl group or halogen In terms of applications, the present invention provides improved retention where the absorbent material is incorporated into body hygiene, in particular diapers for infants or incontinent adults or absorbent pads for protection during the menstrual period. It is characterized by its use as an additive, ie as a super absorbent. Regarding the process for producing the above substances, the present invention provides that at least one isothiazolin-3-one derivative is first added to a water/alcohol mixture, then a hydrocolloidal polyelectrolyte is added and the mixture is then filtered. It is characterized by Hydrocolloidal polyelectrolytes Hydrocolloidal polyelectrolytes, which are insoluble in water and absorb several times their weight in aqueous liquid, can be divided into two broad categories: natural polyelectrolytes on the one hand and synthetic polyelectrolytes on the other hand. (see especially US Pat. No. 4,043,952). (1) The natural polyelectrolyte is advantageously chosen among starch, cellulose or dextran, or anionic derivatives called polysaccharides. Among the anionic groups, mention may be made of carboxyl, sulfonate, sulfate or phosphate. Preferred anionic groups are carboxylalkyl groups and especially carboxylethyl and carboxylmethyl groups. These anionic groups are preferably present in an amount of more than 40%, based on the total number of ionic groups.
and is preferably neutralized by an amount of between 40 and 85% of an alkali metal cation, such as sodium, or by a primary, secondary or tertiary amine. This improves the absorption capacity of the polymer, as is well known. These polyelectrolytes exist in a cross-linked form that makes them water-insoluble but apparently does not change their absorption capacity. This cross-linking is obtained from the formation of covalent bonds by esterification or etherification, which can be done with diols, dihalides or epichlorohydrin as described in UNILEVER NV. Cross-linking can also be realized with transition metals belonging to the following groups of the periodic table: B, B,
B, B, B, B, A, A, A,
A. Among these, mention may be made of aluminum, zirconium, chloro, titanium and zinc. (2) Homopolymers or copolymers of unsaturated carboxylic acids, such as polyacrylic acid or polymethacrylic acid (see especially U.S. Pat. No. 4,043,952), or those obtained from the polymerization of unsaturated sulfonic acids. Homopolymers or copolymers containing sulfonic acids. These homopolymers or copolymers also exist in partially or fully anionic form, and
Cross-linked by the same means as described in (1). Preferred polymers are those containing carboxyl groups, and especially polyacrylic acid or polymethacrylic acid. All these absorb five to several hundred times the weight of their polymers, depending on whether the aqueous liquid is water, urine, or blood, including menstrual blood. . As an indicator, a method such as that described in German Patent No. 2702781 or French Patent No. 2305452 can be used to determine the absorbance. Another important parameter of these polymers is their gelation rate. A good polymer should have a gelation time as short as possible, for example with respect to the Vortex test [G. Goldstein and M. Pierre, Marketing Technology Service In. Site 81, Section-1-18, Publication Miller Freeman (Marketing Technology Service
Insight 81, Section-1-18, Publication
Miller Freeman). Isothiazolin-3-one derivatives The derivatives of the general formula are known as such and also for their bactericidal action. The patentability of the invention does not reside in this already known microbicidal property, but rather in the fact that these compounds
Hydrocolloidal polyelectrolytes can be transferred to the outside and inhibit, if not prevent, the growth of bacteria in all absorbent pads, and thus reduce the development of unpleasant odors. It consists in showing the property of hindering. The following patents describe these derivatives and methods for their preparation: French Patent No. 2139421 describes an extensive list of isothiazolin-3-one derivatives. 〓U.S. Patent No. 3517022 describes isothiazoline-
The preparation and microbicidal properties of 3-one derivatives are described. 〓 and similarly, US Pat. No. 3,544,480, US Pat. No. 3,761,488 and French Patent No. 2,398,505
issue. Among all derivatives corresponding to the general formula: where Y is a hydrogen atom or a _C1 - _C4 -alkyl group, R is a hydrogen atom or a _C1 - _C4 -alkyl group, and R' Preference is given to derivatives in which: has the same meaning as above. And particularly preferred ones are in the general formula:
A derivative in which Y is a methyl group, R is a hydrogen atom, and R' is a hydrogen atom, a halogen atom, or a methyl group. Halogen can in particular be chlorine or bromine.
In order to have improved bactericidal properties while retaining the migration capabilities characteristic of these derivatives, it is desirable that the absorbent material contains at least two derivatives: (A) R′ is chlorine; is a halogen such as, corresponds to the general formula and preferably corresponds to the formula: (In the above formula, R is a hydrogen atom or a _C1 - _C4 -alkyl group, Y is a hydrogen atom or a _C1 - _C4 -alkyl group, and Hal is preferably chlorine.) The other (B ) corresponds to the general formula in which R′ is a hydrogen atom or a C ₁ -C ₄ -alkyl group and preferably corresponds to the formula: (In the above formula, R′ is a hydrogen atom or a C ₁ -C ₄ -alkyl group, Y is a hydrogen atom or a C ₁ -C ₄ -alkyl group, and R is a hydrogen atom or a C ₁ -C ₄ - The absorbent substance preferably contains the following two derivatives: They are known by the formal name: A-5-chloro-2-methyl-isothiazoline-
3-one B-5-methyl-2-methyl-isothiazoline-
3-one A mixture of these products is marketed by ROHM & HAAS, USA under the trade name KATHONC.G., which is an isothiazoline-
Approximately 1.5% by weight of 3-one derivatives (A 1.2% and B
0.3%) and 98.5% by weight of inert substances. Preferably, for absorbent materials containing derivatives (A) and (B), the molar ratio of these two compounds is from 0.5:1 to 8:1. Although isothiazolin-3-one derivatives can be incorporated within a wide weight range based on the weight of the polyelectrolyte without departing from the scope of the invention, if the absorbent material is based on the polyelectrolyte, Preference is given to containing a weight of the isothiazolin-3-one derivative from 1.5 to 750 ppm, particularly preferably from 7.5 to 450 ppm and especially from 10.5 to 150 ppm. As mentioned above, and this is an advantage of the present invention, isothiazolin-3-one derivatives
Migrate to the outside of the polyelectrolyte. It has been found that it is entirely possible, and even desirable, for the absorbent material to also contain metal ions of salts of transition metals known for their bactericidal and flocculating properties, preferably copper or zinc. Ta. These ions can be present in the form of halides or organic salts. A description thereof and numerous enumerations may be found in French Patent No. 2,490,093. However, halides are preferred. Surprisingly, this makes it possible to reduce the amount of isothiazolin-3-one derivatives required, which is a great advantage from a toxicological point of view, and furthermore, isothiazolin-3-one derivatives are However, the metal ions remain in the polymer and thus ensure a further improved bactericidal cover. Furthermore, it increases the gelation rate. The weight ratio of isothiazolin-3-one derivative/transition metal salt is preferably from 0.012:1 to 0.018:
It is 1. If these absorbent materials according to the invention are dispersed in the absorbent pad in the form of granules or powders in proportions known to enable sufficient absorption, they are Eliminate odors whose roots are discussed. The absorbent material according to the invention is preferably obtained at room temperature using a water/methanol or water/ethanol mixture in a ratio of 80/20 to 90/10. If the absorbent material contains salts of metal ions, these are preferably incorporated before the isothiazolin-3-one derivative. The introduction of absorbent substances into the pad can be carried out in several different ways in a known manner, among which the following may be mentioned: - two layers of fluff (cellulose with loosened fibers);
continuous or batch deposition during. A particularly useful variation of this method is described in PCT Patent Application No. 79100120
It is explained by the number. - Mixture with fluff. This fluff is then sandwiched between two pieces of cotton wool or nonwoven fabric. Examples All experiments were carried out with isothiazolin-3-one compound obtained from mixing two derivatives: A-5-chloro-2-methylisothiazolin-3
-one B-5-methyl-2-methylisothiazoline-3
-on (see Rohm & Haas Caisson C.G.). EXAMPLE 1 General method for producing absorbent materials containing KATHON CG and copper in ionic form. Add the metal ions, then the KATHON CG, and finally the polyelectrolyte. The amounts, in parts by weight, are as follows: - Polyelectrolyte 100 - Caisson CG 1.5 - CuCl ₂ 3 After filtration, the polymer powder combined with the other two compounds is recovered. Methanol is recycled. Example 2 Gelation Rate The following three polyelectrolytes were tested: A. Polycarboxylic starch known under the trade name SANWET from SANYO. B. Alkali metal polyacrylate known under the trade name AQUAKEEP from SEITETSU. C Carboxymethyl starch known under the trade name AKUCELL from AKZO. By using the so-called VORTEX test (see description of polyelectrolytes), the following results regarding the gelation rate can be obtained:

[Table] Thus, it is very surprising that the above two
It is clear that the gelation rate is considerably improved by the presence of a seed bactericidal compound. Example 3 Bactericide Migration Inhibition Zone Method Paper disks with a fixed amount of the product to be tested are placed on a plate containing a specific microorganism (e.g. Pseudomonas oleoverans).
Place on the inoculated agar. Place the Petri dish in the refrigerator for 24 hours and then in the oven at 30°C for 18 hours. After the end of the culture, measure the total diameter of the inhibition zone that appears:

[Table] Example 4 Determination of odor intensity Subject to the following three series of tests: - Determination of the detection limit concentration (TC) of the odorous product (see Steiger Chem. Tech. Vol. 1, April 1971 issue) ). - Setting up a scale curve with different samples with several limiting concentrations. - Determination of the effectiveness of disinfectants by determining the odor intensity, referred to in TC units. Examples of use experiments are carried out on sanitary napkins containing Super Absorbent A with 0.1% or 0.15% Caisson CG and 0.2% CuCl ₂ based on the weight of the napkin. On each napkin, 7 ml of bovine blood are deposited along with 1 ml of a bacterial suspension prepared by mixing: 1 ml of a 24-hour culture of Pseudomonas aeruginosa; 1 ml of a 24-hour culture of Escherichia coli; 1 ml of a 24-hour culture of Klebsiella pneumonia 0.8 ml of a 48-hour culture of Proteus mirabilis
5 ml of the strain cultured for 48 hours. Each napkin is then placed in a polyethylene bottle and kept warm at 30°C for 15 hours. The odor intensity is measured under the same conditions. The results are as follows: Caisson CG 0.10% 4 Caisson CG 0.15% 1 Control (no fungicide) 6 Example 5 Final product testing Modified (Cu ²⁺ 5% Diapers containing Super Absorbent B (Aquakeep) were worn by incontinent patients for 12 hours. A control batch containing no modified superabsorbent was tested in parallel. Twelve hours later, olfactory measurements of urine on the diaper and measurements of PH were performed. result:

[Table] That is, the presence of a disinfectant on top of the superabsorbent substantially reduces the generation of products with unpleasant odors and improves the urine pH.
The increase in the stimulant is limited, thus reducing its stimulatory effect.